It is expected that the future society will be a resource-cycling society. In this respect, the realization of energy production using biomass is essential. Active efforts are necessary for the development of resources and environmental technologies to cope with the depletion of fossil fuel, worldwide global warming, etc. Also, technological developments for producing energy from waste environmental resources such as biomass are being fostered. The most abundant biomass on earth is lignocellulose. Lignocellulose is a complex polymer consisting of lignin, cellulose and hemicellulose. Pretreatment is necessary because most of the microorganisms that produce bioenergy and useful chemical materials cannot utilize lignocellulose directly.
After the pretreatment process, sugars that can be utilized by the microorganisms such as glucose, xylose, etc. are generated. But, together with them, fermentation inhibitors which affect the growth of the microorganisms are also generated. The fermentation inhibitors can be largely classified into phenolic compounds and non-phenolic compounds. These toxic substances inhibit the growth of and fermentation by microorganisms, leading to decreased production efficiency of biochemicals or alcohols.
Therefore, detoxification of hydrolysates is necessary before fermentation to obtain products at a high yield. Detoxification methods for removing the inhibitors from the degradation products of lignocellulosic biomass can be largely classified into physicochemical methods and biological methods. These methods do not exhibit high removal efficiency of the fermentation inhibitors and show different removal efficiency for different fermentation inhibitors.
In order to produce bioenergy and chemical materials using microorganisms, development of a detoxification process which is economical and exhibits high efficiency is necessary.